Fractures of the coronoid process are relatively uncommon. It is generally accepted that they account for approximately 1% of all mandible fractures. The coronoid process is infrequently fractured because it is protected by the zygomatic arch.
A diagnosed coronoid fracture is an indication for the surgeon to look for an associated zygomatic arch fracture.
Coronoid fractures are often incidental findings on x-rays when looking for associated maxillofacial injuries.
Diagnosis of a coronoid process fracture would most likely be made on a panoramic x-ray or CT scan. Most commonly, there are other associated fractures. Isolated fractures of the coronoid process are extremely rare.
CT scans provide the best delineation of coronoid fracture morphology. This CT scan demonstrates fracture of the left coronoid process.
Note: associated fracture of mandibular body region.
Clinical pearl: Fracture of the zygomatic arch with medial displacement of fragments can often impinge on the coronoid process of the mandible and cause trismus. CT scan shows coronoid impingement by zygomatic arch fracture.
Very rarely does a fracture of the coronoid process require treatment. Most fractures are simply observed. Some surgeons would advocate removal of the coronoid process in case of persistent mouth-opening restrictions.
In case of a surgically treated comminuted ramus fractures an associated coronoid fracture may be reduced and fixed.